This invention relates to a photographic apparatus, and more particularly to one for use in front projection photography embodying a single lens. With such an apparatus, both the camera and projector and screen combination of the front projection system are used, for example, to photograph a foreground object in front of a background projected on the screen by an image projecting device, such as a projector.
By simply changing transparencies and models, etc. a photographer having numerous background slides or other transparencies can obtain an unusually wide range of photographs simulating real live photographic conditions as if the models were actually photographed on site at the location of the scene projected on the background screen.
The techniques of front projection photography are not new, as is exemplified by the apparatus disclosed in U.S. Pat. Nos. 3,350,980 to George D. Margolin, 3,227,509 to Hobart Baker, 3,322,489 to Eduard Renner, 3,911,450 to Jay Martin Swartz, 2,727,427 to Will F. Jenkins, 3,634,004 to Thomas W. Howard, 3,610,120 to John E. Morse, et al., 3,376,800 to Werner Faasch, 3,675,997 to Roman Andruchiew and 3,920,320 to Donovan K. Ellis, et al.
In such examples of the prior art, separate lenses are utilized for focusing a projected image on a screen, and for focusing an image of a film plane. Additionally, beam splitting sheets, generally semi-silvered mirrors, are used to separate the projected image and the image to be directed to a film plane of a camera, be it a television or motion picture camera or an ordinary still camera, such as a single lens reflex camera.
One disadvantage of such front projection systems is the problem concerning shadow cast by the foregoing objects on the background, which cannot be completely eliminated and causes a "black line" around some part of the foreground object. Obviously, any such shadow or dark edge outlines which are commonly referred to as "black line" defects, would destroy the impression of reality.
Consequently, such front projection systems of the prior art using two separate lenses are precision manufactured and relatively expensive as alignment problems are critical in that positioning of the two lenses must be exact. Also, as the lenses cannot be a perfectly matched pair, their focal lengths are slightly different, and they must be mounted so that the optical centers of the lenses coincide, and they must be almost perfectly perpendicular and/or parallel to the other optical elements of the system in order to minimize the black edge lines and reduce such black line shadow effects to an acceptable level. As a result, mounting arrangements are made with adjustable means for enabling the photographer to control such shadow problems and to maintain the proper angular relationship between the projector, camera and the beam splitter.
Accordingly, it is a principal object of the invention to provide a novel and improved front projection system.
Another object of the invention is to provide a new and improved device for eliminating the shadow or dark edge outlines without the need for major adjustments of the elements of the system.
Yet another object of the invention is to provide a front projection system which includes only a single lens for photographing an object and for projecting a transparency or image onto a screen.
Yet still another object of the invention is to provide a front projection system which is generally simple in construction, more economical to manufacture and one which is relatively simple to set up and operate.
These, and other objects of the invention, as well as the advantages of the invention, will become more fully apparent from a consideration of the accompanying specification when taken in conjunction with the drawing forming a part thereof and in which exemplary embodiments are described.